Ground structure for a cable card assembly of an electrical connector

Abstract

A cable card assembly includes a circuit card having cable conductors at a cable end and cables terminated to the circuit card having signal conductors and ground shields surrounding the corresponding signal conductors to provide electrical shielding for the signal conductors. The signal conductors include exposed portions terminated to corresponding cable conductors. The cable card assembly includes a ground bus electrically connected to the ground shields. The ground bus includes a molded body having tunnels receiving the exposed portions of corresponding signal conductors. The molded body is contoured to control impedance along the exposed portions of the signal conductors.

What is claimed is: 
     
       1. A cable card assembly for an electrical connector comprising:
 a circuit card having an upper surface and a lower surface, the circuit card having a cable end and a mating end opposite the cable end, the circuit card having mating conductors at the mating end for mating with a mating electrical connector, the circuit card having cable conductors at the cable end; 
 cables terminated to the circuit card, the cables including signal conductors and ground shields surrounding the corresponding signal conductors to provide electrical shielding for the signal conductors, the signal conductors including exposed portions extending forward of the ground shields, the exposed portions being terminated to corresponding cable conductors; and 
 a ground bus separate and discrete from the circuit card and being coupled to the circuit card, the ground bus being electrically connected to the ground shields to electrically connect the ground shields of the cables, the ground bus including a molded body including tunnels receiving the exposed portions of corresponding signal conductors, the molded body being contoured to control impedance along the exposed portions of the signal conductors, wherein the ground bus includes cable pockets at a rear of the ground bus shaped to follow contours of the ground shield to interface with an outer end and both sides of the ground shield. 
 
     
     
       2. The cable card assembly of  claim 1 , wherein the ground bus has a spacing between the molded body and the exposed portions of the signal conductors along the lengths of the exposed portions, the spacing being variable along the lengths of the exposed portions. 
     
     
       3. The cable card assembly of  claim 1 , wherein the exposed portion includes an insulation exit end and a distal end, the molded body being closer to the exposed portion at the insulation exit end compared to the distal end. 
     
     
       4. The cable card assembly of  claim 1 , wherein the ground bus includes a constriction wall and a front portion extending forward of the constriction wall to a front of the ground bus, the molded body being closer to the exposed portions along the constriction wall compared to along the front portion. 
     
     
       5. The cable card assembly of  claim 4 , wherein the constriction wall includes a first well and a second well with a bulge between the first well and the second well, the first well receiving a first signal conductor of the signal conductors, the second well receiving a second signal conductor of the signal conductors. 
     
     
       6. The cable card assembly of  claim 4 , wherein the constriction wall is located immediately forward of the ground shields. 
     
     
       7. The cable card assembly of  claim 4 , wherein the cable pockets are rearward of the constriction wall. 
     
     
       8. The cable card assembly of  claim 1 , wherein the ground bus includes cable pockets receiving the corresponding cables, each cable pocket defined by an end wall and sidewalls extending from the end wall, the end wall interfacing with an outer end of the corresponding cable, the side walls interfacing with opposing sides of the corresponding cable. 
     
     
       9. The cable card assembly of  claim 8 , wherein the end wall includes solder openings receiving solder to electrically connect the end wall to the ground shields. 
     
     
       10. The cable card assembly of  claim 1 , wherein the molded body includes an outer wall and separating walls extending from the outer wall, the separating walls and the outer wall forming the tunnels. 
     
     
       11. The cable card assembly of  claim 10 , wherein the molded body includes curved transitions between the outer wall and the separating walls. 
     
     
       12. The cable card assembly of  claim 10 , wherein the separating walls have variable thickness between a front and a rear of the ground bus. 
     
     
       13. The cable card assembly of  claim 10 , wherein the separating walls have interior surfaces facing the tunnels, the interior surfaces being nonplanar. 
     
     
       14. The cable card assembly of  claim 1 , wherein the molded body is a monolithic, unitary structure. 
     
     
       15. The cable card assembly of  claim 1 , wherein the molded body is a diecast body. 
     
     
       16. The cable card assembly of  claim 1 , wherein the ground bus extends between a front and a rear, the ground bus having an inner end mounted to the circuit card and an outer end opposite the inner end, the ground bus includes mounting pins extending from the inner end, the mounting pins being coupled to the circuit card. 
     
     
       17. The cable card assembly of  claim 1 , wherein the ground bus includes mounting pins received in ground vias of the circuit card, the mounting pins being press-fit into the ground vias to electrically connect the ground bus to the circuit card at solderless connections. 
     
     
       18. The cable card assembly of  claim 1 , wherein the tunnels extend between a rear and a front of the ground bus, the tunnels being separated by separating walls, each tunnel receiving a pair of the signal conductors, the separating walls providing electrical shielding between the pairs of the signal conductors. 
     
     
       19. A ground bus for a cable card assembly including a circuit card and cables terminated to the circuit card, the ground bus comprising:
 a molded body having a front and a rear extending between an inner end and an outer end opposite the inner end, the molded body having a first side and a second side, the inner end configured to be mounted to the circuit card, the molded body configured to be electrically connected to ground shields of the cables, the molded body being electrically conductive to electrically connect the ground shields; and 
 separating walls at the inner end forming tunnels, the tunnels being open at the rear to receive signal conductors of the corresponding cables of the cable card assembly, the separating walls providing electrical shielding for the signal conductors in the tunnels, the separating walls having variable thickness to contour the tunnels to control impedance along the signal conductors, wherein the tunnels include cable pockets at the rear of the ground bus shaped to follow contours of the ground shields to interface with an outer end and both sides of the ground shields. 
 
     
     
       20. An electrical connector comprising:
 a housing having walls forming a cavity, the housing having a mating end at a front of the housing configured to be mated with a mating electrical connector; and 
 a cable card assembly received in the cavity of the housing, the cable card assembly including a circuit card, cables terminated to the circuit card, and a ground bus coupled to the circuit card, the circuit card having an upper surface and a lower surface, the circuit card having a cable end and a mating end opposite the cable end, the circuit card having cable conductors at the cable end, the circuit card having mating conductors at the mating end, the mating end of the circuit card configured to be plugged into a card slot of the mating electrical connector, the cables including signal conductors and ground shields surrounding the corresponding signal conductors to provide electrical shielding for the signal conductors, the signal conductors having exposed portions extending forward of the cable shields, the exposed portions being terminated to corresponding cable conductors, the ground bus being electrically connected to the ground shields to electrically connect the ground shields of the cables, the ground bus including a molded body including tunnels receiving the exposed portions of corresponding signal conductors, the molded body being contoured to control impedance along the exposed portions of the signal conductors, wherein the ground bus includes cable pockets at a rear of the ground bus shaped to follow contours of the ground shield to interface with an outer end and both sides of the ground shield.